Heat setting fibrous cotton esters



Wearing apparel, such as a United States Patent O r 3,356,446 HEAT SETTING'FI ROUS COTTON ESTERS Albert S. Cooper, Jr., Metairie, Alton L. Murphy, New Orleans, and William G. Sloan, Metairie, La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Aug. 22, 1963, Ser. No. 303,969 12 Claims. (Cl. 8131) A nonexclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of theUnited States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to the production and use of fibrous esterified cellulose textiles having improved resistance to creasing and the ability to retain creases. More particularly this invention relates to a process of heat curing or heat setting fibrous cellulose esters in the form of fabrics to improve their resistance to creasing and also the retention of creases put in prior to or during the heat setting processes.

The products prepared according to the process of this invention exhibit greatly improved resistance to creasing or wrinkling and also the property of retaining creases that are put in the fabric prior to or during the process. Resistance to creasing may be defined as the ability of a textile material to withstand deformation by the forces normally encountered in wearing a garment or in laundering the item of Wearing apparel. Crease retention may be defined as the ability of an article of pleated skirt, to go through one or more laundering cycles and have essentially an unchanged appearance.

Those familiar with the art will immediately recognize crease resistance and crease retention as described above as the most desirable characteristics of easy care or wash and Wear garments. Those familiar With the art will further recognize that a textile material that can be given improved crease resistant properties after fabrication into a garment will permit easy manufacture of specialized garments that require creases, pleats, and folds. Crease resistance is particularly desirable for all items of Wearing apparel that may require ironing and crease retention is particularly desirable in mens pants, coats,

, pleated skirts for ladies, and any garment that must be recreased or pleated because of alterations in length.

In general, the process of this invention involves the or changes 3,356,446 Patented Dec. 5, 1967 ICC dry or wet heating of fibrous cotton cellulose esters in the form of fabric. The operable temperature can vary from 127 C. to as high as 250 C., the upper limit being the onset of heat degradation in the material under treatment and the lower limit being the temperature required to cause a pseudo softening of the fibers that permits rearrangement of the internal molecular structure of the fibers. Furthermore, the time-temperature relationship of this process is affected by the presence of organic and inorganic solvent vapors. In the case of Water, present as steam, the temperature required for heat curing is reduced as well as the time. The time requirements for the treatments disclosed in this invention can vary from 30 seconds to as much as 24 hours. The more extended heating periods are employed with the lower treating temperatures in the absence of solvent vapors.

Although the invention applies directly to fibrous cellulose esters of cotton fabric, it is anticipated and expected that fibrous cellulose esters of cotton fibers and yarns could be treated as herein described and then be spun into yarns and woven into fabric as the case may be to obtain essentially the same results.

The heat treatment of fibrous cellulose esters of cotton fabric can be carried out as a continuous operation or as a batch operation. The treatments described in the specific examples which follow were carried out in batch operations utilizing standard laboratory ovens, standard autoclaves, and a specially constructed autoclave for use at high temperatures and pressures-the heavier materials of construction being theonly difference from standard autoclaving equipment. The specific example cited in which tension was applied simultaneously to the warp and fill direction of the fabric utilized a small pin frame for convenience. No effort was made to measure the amount of tension and the example is cited to illustrate that improved crease resistance may be obtained when tension is applied as well as when the treatment is made without tension.

The specific examples are simple batch type processing treatments but it will be recognized that a variety of known means can be employed to carry out the treatment in batch or continuous operation. In the specific examples and in the tabular data which follow we use the term partially esterified cotton to describe cotton that has been treated with an esterifying agent so as to esterify part of the available hydroxyl groups on the cellulose without materially changing the physical appearance of the cotton itself. In the case of a specific esterifying agent the material is referred to by the name of the specific acyl group used for the substitution. As an example if acetic Example 1 (DS 1.25) X 80 PRINT CLOTH AFTER VARIOUS HEAT TREATMENTS FOR VARIOUS PERIODS OF TIME Crease Recovery Condition of Treatment Angle Warp Plus Filling Directions Time Temperature Atmosphere Tension Dry, Wet,

degrees degrees Control Unheated 209 137 30 min 0 Dry N0 235 147 4 hrs 160 C. Dry N 0 245 162 24 hrs 160 C Dry No 241 I 150 30 sec 250 0 Dry N0 236 190 4 min 250 C Dry N0 216 164 15 min 250 C Dry N0 242 174 30 min 127 C 20 p.s.i.g. steam No 251 180 90 min 127 C do No 247 192 10 min 177 C 120 p.s.i.g. steam No 225 184 30 min 177 C d0 N0 245 185 30 min 127 C 20 p.s.i.g. steam Yes 247 202 Example 2 washing machine using a neutral detergent. After each washing they were tumbled-dried in a household drier. After cycles the samples retained their creases and were assigned Wash and wear ratings of 3 to 4 by the subjective comparison test. The degree of substitution of the mixed ester was about 1.0.

Example 6 A sample of partially acetylated 80 X 80 print cloth was wet out in water and embossed on commercial embossing equipment at a high enough temperature to dry TABLE II.-CREASE RECOVERY ANGLE OF PARTIALLY ACETYLATED (DS 1.2) 48 X 48 SHEETING AFTER VARIOUS HEAT TREATMENTS FOR VARIOUS PERIODS OF TIME Crease Recovery Condition of Treatment Angle Warp Plus Filling Directions Time Temperature Atmosphere Tension Dry, Wet,

degrees degrees 200 124 Dry 233 155 Dry 241 102 Dry 237 160 Dry 232 190 Dry 235 184 Dry 240 188 p s Ste 238 185 dO 231 195 120 p.s.i.g. Steam 223 178 do No 232 193 20 p.s.i.g. Steam... Yes 237 197 Example 3 the fabric during the embossing treatment. The sample TABLE Ill-GREASE RECOVERY ANGLE OF OTHER PARTIALLY ESTERIFIED 80 X 80 PRINT CLOTH HEAT TREATED BY AUTOCLAVING IN VET STEAM AT 20 P.S.I.G. AND 127 C.

A sample of 8.5 oz. partially acetylated sateen was placed in a sunburst pleating form and autoclaved at 177 C. under 120 p.s.i.g. steam pressure for minutes. The sample was cooled to room temperature and removed from the pleating form. Very sharp creases were imparted to the fabric. The pleated fabric was washed in a home type washing machine using a neutral detergent. After one washing cycle the sample was tumbled dried in a home type drier. Subjective evaluation showed that the sample had retained all of the pleats and was essentially unchanged by the washing treatment whereas the pleats were completely removed from an untreated cotton control sample that had received the same treatments. After 20 washings and drying cycles the partially acetylated cotton sample still retained all of the pleats and required only touchup ironing to restore it to its original condition. The degree of substitution of this acetylated fabric was 1.2.

Example 5 Creases were pressed in small samples of partially isobutyrylated, partially acetylated-isobutyrylated (mixed ester), and partially propionated 80 X 80 print cloth and autoclaved at 177 C. under 120 p.s.i.g. steam pressure for 30 minutes. The samples were. washed in a household was autoclaved for 30 minutes at 127 C. under 20 p.s.i.g. steam pressure. After 5 household washing and tumbledrying cycles the tree bark embossed pattern was essentially unchanged. The partially acetylated print cloth had a degree of substitution of 1.25.

We claim:

1. A process for imparting improved wrinkle resistance and crease retention to a fibrous cotton cellulosic ester prepared by esterifying cotton fibers without materially changing the physical appearance thereof and having a degree of acyl substitution of about from .7 to 1.25, and said ester being in fabric form and of predetermined configuration, which comprises apply dry heat thereto at a temperature of about from to 250 C. for a period of time of about from 10 minutes to 24 hours, the higher temperature being used for the lower periods of time.

2. A process for imparting improved wrinkle resistance and crease retention to a fibrous cotton cellulosic ester prepared by esterifying cotton fibers without materially changing the physical appearance thereof and having a degree of substitution of about from .7 to 1.25 selected from the group consisting of cellulose acetate, cellulose propionate, and cellulose iso-butyrate, the said cellulosic ester being in fabric form, and of predetermined configuration, which comprises applying dry heat thereto at temperatures of about from 160 to 250 C. for periods of time of about from 30 minutes to 240 minutes, the higher temperatures being used with the lower periods of time.

3. The process of claim 2, wherein the cellulose ester fabric is cellulose acetate.

4. The process of claim 2, wherein the cellulose ester fabric is cellulose propionate.

5. The process of claim 2, wherein the cellulose ester fabric is cellulose iso-butyrate.

6. A process for imparting improved wrinkle resistance and crease retention to a fibrous cotton cellulosic ester prepared by esterifying cotton fibers without materially changing the physical appearance thereof and having a degree of acyl substitution of about from .7 to 1.25, said ester being in fabric form and of predetermined configuration, which comprises applying wet steam at a gauge pressure of about from 20 p.s.i. to 120 p.s.i. thereto for a period of time of about from minutes to 90 minutes.

7. The process of claim 6, wherein the fibrous cotton cellulosic ester is a mixed acetate-isobutyrate cellulose and the wet steam is applied at a gauge pressure of p.s.i.

8. A process for imparting improved wrinkle resistance and crease retention to a fibrous cotton cellulosic ester prepared by esterifying cotton fibers without materially changing the physical appearance thereof and having a degree of substitution of about from .7 to 1.25 selected from the group consisting of cellulose acetate, cellulose propionate, and cellulose iso-butyrate, the said cellulosic ester being in fabric form, and of predetermined configuration, which comprises applying Wet steam at a gauge pressure of about from 20 p.s.i. thereof for a period or time of about from 10 minutes to minutes.

9. The process of claim 8, wherein the fibrous cotton cellulosic ester is cellulose acetate.

'10. The process of claim 8, wherein the fibrous cotton cellulosic ester is cellulose iso-butyrate.

11. The process of claim 8, wherein the fibrous cotton cellulosic ester is cellulose iso-butyrate.

12. A process for imparting improved wrinkle resist- 25 ance and crease retention to a fibrous cotton cellulosic ester prepared by esterifying cotton fibers without materially changing the physical appearance thereof and having a degree of substitution of about from .7 to 1.25

selected from the group consisting of cellulose acetate, cellulose propionate, and cellulose iso-butyrate, the said cellulosic ester being in fabric form, and of predetermined configuration, which comprises applying dry heat thereto at temperatures about from to 250 C. for periods of time about from 10 minutes to 24 hours, the higher temperatures being used with the lower periods of time.

References Cited UNITED STATES PATENTS 1,716,255 6/1929 Woodman et al. 264324 X 2,047,230 7/1936 Schneider 264324 X 2,047,240 7/1936 Whitehead 264324 X 2,190,807 2/1940 Steinberger 264324 X 2,313,173 3/1943 Schneider et al. 8131 X 3,148,236 8/1964 Nirenberg 264324 FOREIGN PATENTS 442,669 2/ 1936 Great Britain. 442,670 2/1936 Great Britain.

OTHER REFERENCES Preston et al.: Journal of the Society of Dyers and Colourists, June 1953, pp. 201-202.

Fortess: American Dyestuff Reporter, vol. 44, p. 322- p. 323 (1955).

NORMAN G. TORCHIN, Primary Examiner.

J. C. CANNON, Assistant Examiner. 

1. A PROCESS FOR IMPARTING IMPROVED WRINKLE RESISTANCE AND CREASE RETENTION TO A FIBROUS COTTON CELLULOSIC ESTER PREPARED BY ESTERIFYING COTTON FIBERS WITHOUT MATERIALLY CHANGING THE PHYSICAL APPEARANCE THEREOF AND HAVING A DEGREE OF ACYL SUBSTITUTION OF ABOUT FROM .7 TO 1.25, AND SAID ESTER BEING IN FABRIC FORM AND OF PREDETERMINED CONFIGURATION, WHICH COMPRISES APPLY DRY HEAT THERETO AT A TEMPERATURE OF ABOUT FROM 160 TO 250*C. FOR A PERIOD OF TIME OF ABOUT FROM 10 MINUTES TO 24 HOURS, THE HIGHER TEMPERATURE BEING USED FOR THE LOWER PERIODS OF TIME. 